Patent GB-918472-A (GB)
Title: Logic systems
IPC: G09F9/313
Filed: 1960-06-20
Abstract: 918,472. Monogrammic signs. BECKMAN INSTRUMENTS Inc. June 20, 1960 [March 14, 1960], No. 21516/60. Class 118. [Also in Group XL (b)] Binary signals at a number of input terminals operate light sources, and light-responsive devices generate output signals, the light paths between said sources and devices being so arranged as to produce a set of output signals having a predetermined logical relationship to the input signals. As described, the invention is used to convert the multiple individual neon lamp display of a decade binary counter into the type of segmented display which provides a single-position Arabic numeral type presentation, the segments of which are illuminated by neon lamps or electro-luminescent elements. In an arrangement described but not claimed, the individual read-out lamps 20 ... 29, Fig. 2, of a decade counter are each arranged to illuminate one or more of the photo-conductors 50 ... 56 associated respectively with segments 10 ... 16 of the final display panel 30. The light paths from the lamps 20 ... 29 to the photo-conductors 50 ... 56 are represented by arrows, such as 57 between 20 and 53 and 58 ... 62 between 21 and 50, 51, 53, 54, 56. The segments 10 ... 16 are normally illuminated by neon lamps 31 ... 37, respectively, fed through resistances 39 ... 45, respectively, from a voltage source 38. The segment lamps 31 ... 37 are shunted by photo-conductors 50 ... 56 respectively, so that the illumination from a segment lamp is inhibited when its photoconductor is illuminated by one of the lamps 20 ... 29. Thus the illumination of one of the lamps 20 ... 29 results in the inhibition of those segments of the display 30 appropriate to exhibit the corresponding Arabic numerals by the remaining illuminated segments. In a modification, which falls within the scope of the invention claimed and which reduces to two the maximum number of light paths to a single photo-conductor, and to three the maximum number of photo-conductors illuminated by a single lamp, an extra input lamp is illuminated whenever an odd numeral is to be displayed, and an extra lamp and two photo-conductors are provided to form a pair of switches maintained in mutually opposite states, Fig. 4 (not shown). A suitable lay-out for the components of this modified circuit is described, Figs. 5 to 8 (not shown). In another embodiment, the display panel 76, Fig. 9, comprises eleven segments 77 ... 87, of which segments 85 ... 87 are permanently illuminated from the source 38. The other segments, each of which is illuminated by a series pair of neon lamps, are selectively inhibited over conductors 90 ... 97 by shunting across the pair a single lamp of the series 125, 129 ... 136, 146 ... 151 which are selectively rendered conducting by appropriate illumination of one or more of the photo-conductors 115 ... 122 through which their earth connections are made. The individual read-out lamps 20 ... 29 of the decade counter, a lamp 70 illuminated with every odd number, and the lamps 129, 149 have light-paths to the photoconductors indicated by the curved arrows. Thus, for example, if the numeral " one " is to be displayed, the read-out lamps 21, 70 are energized whereby the photo-conductor 115 is illuminated to energize lamp 132 to inhibit segment 81, and the photo-conductor 117 is illuminated to energize lamps 130, 131 and 129 so that segments 80, 83, 77 are inhibited and photo-conductor 119 is illuminated to energize lamps 135, 136 to inhibit segments 78, 84. Other numberals are displayed by different selections of the inhibiting lamps. The display panel segments may alternatively comprise electro-luminescent light sources.